During a check-up of a driver by a police patrol in the Czech Republic by means of a breath analyzer of Dräger Co. an alcohol blood level of 0.50 g/kg was assessed. Later the driver reported that before the test he used at 30- and 5- minute intervals the drug Stopangin spray. In the Institute of Forensic Medicine the authors made an experiment which revealed that 22 minutes after administration of the drug the apparatus gave a negative result. Agreement with these conclusions was expressed also by a representative of Dräger Co. and the results were published as an expert opinion with a recommended procedure for the police of the Czech Republic in the South Moravian region.

        Key words: Stopangin spray - breath analyzer of Dräger Co. - effect on alcohol level